Retrofit和RxJava多个请求完成

Question

我需要去做:

1. 请求来自不同网站的2个新闻列表
2. 结合请求的结果
3. 按日期对项目排序
4. 获取10条最新消息
5. 保存他们
6. 显示完整的消息

例如,我有两个可观察量:

Observable<RegionalNews> regionalNews;
Observable<NationalNews> nationalNews;

public interface NewsNationalService {
  @GET("news/national")
  Observable<News> getNationalNews();
}

public interface NewsRegionalService {
  @GET("news/regional")
  Observable<News> getRegionalNews();
}

Answer 1

您可以使用zip运算符调用2个异步请求,并在响应时保存或处理其数据.

例如.

以下是两个 Observable

Observable<ResponseOne> responseOneObservable = getRetrofitClient().getDataOne()
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread());

Observable<ResponseTwo> responseTwoObservable = getRetrofitClient().getDataTwo()
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread());

使用zip以上两个操作符Observable如下.

Observable<ArrayList<TestData>> testDataObservable = Observable.zip(responseOneObservable, responseTwoObservable, new Func2<ResponseOne, ResponseTwo, ArrayList<TestData>>() {
            @Override
                public ArrayList<TestData> call(ResponseOne responseOne, ResponseTwo responseTwo) {
                  ArrayList<TestData> testDataList = new ArrayList();
                      // process data from response responseOne & responseTwo
                  return testDataList;
            } 
    })
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(new Subscriber<ArrayList<TestData>>() {

        @Override
        public void onNext(ArrayList<TestData> testDataList) {

        }

        @Override
        public void onCompleted() {
            Log.d(TAG, "onCompleted" ); 
            // you can show alert here or do something when completed 
        }

        @Override
        public void onError(Throwable t) {
            Log.d(TAG, "onError Throwable: " + t.toString() );
        }
    });

Answer 2

如果您不想对合并后的结果做特定的事情，那么merge（）就足够了：

Observable<RegionalNews> regionalNews = ...;
Observable<NationalNews> nationalNews = ...;

Observable
.merge(regionalNews, nationalNews)
.ignoreElements()
.observeOn(AndroidSchedulers.mainThread())
.doOnComplete(() -> { /* show alert */ })
.subscribe()